Heat exchange device



March 22, 1932. A. HALL-BROWN ET AL 1,350,373

HEAT EXCHANGE DEVICE Filed June 24', 1927 2 Sheets-Sheet 1 Ill 5 Z 3 INVENTOR W M- M ATTORNEYS HEAT EXCHANGE DEVICE & INVENTOR gww ATTORN EYS Patented Mar. 22, 1932 UNITED STATES PATENT OFFICE ABCHIBALD HALL-BROWN, OF. PURLEY, AND EDWIN WALTER JONES, OF LINCOLN, ENGLAND, ASSIGNORS TO THE BAIBCOGK & WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY HEAT EXOHAN GE DEVICE Application filed .Tune 24, 1927, Serial No. 201,080, and in Great Britain July 23, 1926.

Our invention more particularly relates to heat exchange devices comprising a rotary member having two groups of passages separated by walls and preferably alternating with each other, two different fluids of different temperatures flowing through the respective groups of passages. The heat exchange device also preferably comprises a stationary section. Our invention is particularly applicable to an air heater in which air is heated by waste gases, though it will, of course, be understood that our invention is not limited thereto. 2

Our invention will best be understood by the line 33 of Fig. 1; Figs. 4 and 5 are sections taken on the lines 4-4 and 5-5, respectively, of Fig. 1, and Fig. 6 is a plan view, partially broken away, of the top of the stationary air heater.

Like reference characters indicate like parts throughout the drawings.

Referring now to the drawings, 10 indicates generally a rotaryheat exchange device which is preferably in the form of a fan or impeller, provided with hollow impeller blades 11 which may be formed by parallel plates preferably curved, as best shown in Figs. 4 and 5, and preferably attached at their outer ends to an annular member 12, and at their inner ends to an annular member 13, the fan comprising said annular members being secured to an operating shaft 28 by a plate 131. The impeller blades thus form two groups of alternating passages. Between the blades are the passages 14 of one group for one fluid such as air, and the hol low spaces within the blades form the passages 15 of the other group for another fluid, which is here shown as a waste gas. The blades are preferably tapered as best shown in Fig. 1, so that their inner surfaces lie in a conical surface co-axial, in the embodiment illustrated, with a conical annulus 16 adjacent to the fan or rotary heat exchange device.

Assuming that the heat exchange device is Y .ing 17 adjacent to the fan or rotary member 10 is formed with openings 19 through which air from the casing 17 enters the air passages 14 in the fan, flowing in the direction indicated by the arrows in Fig. 1.

The stationary section of the heat exchange device, in the embodiment illustrated, comprises a plurality of cells indicated generally at 20, each cell preferably being formed by two plates closely spaced, as shown in Fig. 2, and suitably closed at their edges, the air flowing through the cells, and the waste gases flowing between the cells. Distance pieces (not shown) may be fixed to the walls of the cells to maintain the required spacing of the cells in spite of any tendency to distortion I due to heat influence. The cells, in the embodiment illustrated, are suitably attached to top plates-21 provided with slots or open ings 22 registering with the cells, the plates 21 being supported by meanswhich'need not be specifically described.

Gas passages 23 are thus formed between each two adjacent cells. Heated gases from a furnace, or the like, enter the stationary part of the heat exchange device at 24, and flow over the cells through which the air is passing to the annular member 16 and enter the inner portion of the fan and are discharged in a general radial direction through the passages 15 to a passage 25 communicatin with the stack 26.

n the embodiment of our invjntion illustrated, the fan; or rotary member is actuated secured the fan or rotary member.

The cells 20 of the stationary heat exchange?- device are preferably each divided transversely of the device by partitions 29 extending down into the cells, but short of the bottom thereof, as illustrated in Fig. 1. Air passages 30 are formed in the upper portion of the device between the plates 21 and the roof 32 and vertical partition plates 31 are preferably provided which register with the partitions 29 in the cells, so that the air which is discharged from the passages 14 in the fan flows over the annulus 16 to the passages 30, the air being compelled to flow downwardl into each of the cells and under the end 0 the partitions 29 upwardly to the next succeeding portion of the passage 30, and is eventually discharged throu h the heated air outlet 33. The air, therefore, discharged from the fan to the passages is compelled to pass downwardly and upwardly through the cells in thin sheets or films interleaved with films of hot gases separated from the air filfilS by the thin vertical metal walls of the ce s.

Elements of a scraper gear are indicated at '35, an access opening at 36, and a soot hopper The rotar member or fan constituting one section of tiie heat exchanger illustrated in our invention, produces eflective heat transfer between the hot gases flowing through the passages in the fan, and the air flowing through passages alternating with the passages through which the hot gases flow. Furthermore, the single fan serves to force both air and heated gases through not only the fan or rotary member, but through the sta-' tionary section of the heat exchange device. The combination, therefore, is particularly effective since it not only promotes heat transfer in the fan itself, but increases the velocity through the stationary heat exchange device, thereby increasing the heat exchange therein.

The fan being disposed at the cold end of I the heat exchange apparatus, it is practicable to use a small-sized fan.

The arrangement is particularly applicable to a stationary heat exchange device where thin films of air are separated from thin films of the hot gases, thereby creating high resistance to the flow of gases therethrough, since the heat transfer roughly varies in proportion to the resistance of the flow of gases therethrough.

By supporting or suspending the plates or walls of the stationary cells 20 from one end only and preferably from the upper end as illustrated, and leaving the lower ends, free,

- it will be noted that the walls are free to exgroup alternating with those of the other group, the rotary section being constructed and arranged to cause fluids having different temperatures to flow through the respective groups of passages of both of said sections.

2. A heat exchange device comprising a rotary section having two groups of passages separated by walls, the passa es of one group alternating with those of the other group, said heat exchange device also comprising a stationary section, the heated gases passing over said stationary section, and then through the passages of one group of said rotary section, and the air passing through the passages of the other group of said rotary section, and then over said stationary section.

3. A heat exchange device comprising a rotary section and a stationary section, each of said sections having two groups of passages separated by walls, the passages of one group alternating with those of the other ,group, the rotary section being constructed and arranged to cause fluids havingdiflerent temperatures to flow through the respective groups of passages of both of said sections the rotary section being located at the cold end of said device.

4. A heat exchange device comprising a rotary member having an inner and outer conical surface and provided with two groups of passages separated by walls, the passages of one group alternating with those of the other, one group extending from said inner conical surface outwardly through said rotary member, means for rotating said member, and means for conducting relatively hot and relatively cool gases to and from said passages.

5.- A heat exchange device comprising a hollow vane fan provided with one group. of passages between the vanes and another group of passages through the vanes, said vanes being formed both inside and outside to propel the two fluids, while heat is being transferred from one to the other, and means to prevent gases passing through said respective passages from commingling.

6. A heat exchange device comprising a stationary heat transfer device having two groups of passages separated by walls, and a hollow vane fan having one group of passages between the vanes and another group of passages through the vanes, the groups of passages of said fan communicating with the respective groups of passages of said stationary section, whereby said fan propels the gases through each group of passages of both said stationary heat transfer device and said rotary fan.

7. A heat exchange device comprising a rotary member having two groups of passages having difl'rent teignperatures to flow through the respective passa es, revolvin parts of said rotary member undin sai passages on all sides so that the flui that flows through them is inclosed on all sides by revolvin arts. I

K CHIBALD HALL-BROWN. EDWIN W. JONES. 

